1. Field of the Invention
The present invention relates to a cyclone-type dust collecting apparatus for a vacuum cleaner, and more particularly, to a grill assembly of a cyclone-type dust collecting apparatus for a vacuum cleaner for separating dust or filth from the air whirling in the cyclone-type dust collecting apparatus.
2. Description of the Prior Art
A cyclone-type dust collecting apparatus separates particles from a fluid by using a centrifugal force. Due to its simple structure and high resistance to high temperature and high pressure, the cyclone-type dust collecting apparatus has been used in many industrial fields and even in vacuum cleaners.
The vacuum cleaner having the cyclone-type dust collecting apparatus is constructed such that relatively large particles of contaminants are firstly filtered in the cyclone-type dust collecting apparatus before contaminant-laden air flows to a paper filter of the cleaner body. Since the amount of contaminants that have to be filtered at the paper filter is decreased by the cyclone apparatus, the life span of the paper filter is lengthened. Also, problems like suction force deterioration and motor overload, which are caused by a clogged or obstructed paper filter, can also be prevented.
U.S. Pat. No. 6,195,835 (application Ser. No. 09/388,532) issued Mar. 6, 2001 to the same applicant disclosed a vacuum cleaner having the above-described cyclone-type dust collecting apparatus.
FIG. 1 is a sectional view schematically showing the structure and operation of the cyclone dust collecting apparatus for a vacuum cleaner as disclosed in U.S. Pat. No. 6,195,835.
As shown in FIG. 1 of the present application, the cyclone-type dust collecting apparatus 10 disclosed in U.S. Pat. No. 6,195,835 is disposed on extension pipes 1a and 1b of the vacuum cleaner.
By using the centrifugal force of the whirling air, the cyclone-type dust collecting apparatus 10 separates and collects dust and filth from contaminant-laden air that is drawn in through a suction port of the cleaner. The cyclone-type dust collecting apparatus 10 includes a cyclone body 20, a dust receptacle 30 and a grill assembly 40.
The cyclone body 20 has a first connection pipe 21 connected to the extension pipe 1a at the suction port of the cleaner, a second connection pipe 22 connected to the extension pipe 1b at a body of the cleaner, an air inlet 23 interconnected with the first connection pipe 21 and an air outlet 24 interconnected with the second connection pipe 22. The contaminant-laden air is drawn into the cyclone body 20 through the air inlet 23, forming a vortex of air.
The dust receptacle 30 is removably connected to the cyclone body 20, and collects the contaminants that are separated from the air by the centrifugal force of the vortex of air generated in the cyclone body 20.
The grill assembly 40 is disposed on the lower side of the air outlet 24 of the cyclone body 20 to prevent contaminants collected in the dust receptacle 30 from entering into the cleaner body. The grill assembly 40 has a grill supporting portion 41, a conical grill portion 42 and a cylindrical grill portion 43, which are integrally formed with each other. The cylindrical grill portion 43 has a plurality of fine holes 43a interconnected with the air outlet 24. The cylindrical grill portion 43 has a conical dust blocking plate 44 formed on a distal end.
In the vacuum cleaner having the cyclone-type dust collecting apparatus as described above, contaminant-laden air is drawn into the vacuum cleaner along the pipe 1a by the suction force that is generated at the suction port of the cleaner, and the air flows into the cyclone body 20 through the first connection pipe 21 in a diagonal or downwardly helical flow and direction. The air is diagonally drawn into the cyclone body 20 into a whirling helical current that moves downward to the bottom of the dust receptacle 30. During this process, contaminants are separated from the air by the centrifugal force of the whirling air current, and are collected in the dust receptacle 30 after falling along an inner wall of the dust receptacle 30. The air reaching the bottom of the dust receptacle 30 turns in direction and moves upward in a smaller radius helical flow, and flows outside of the cleaner body through the fine holes 43a of the grill assembly 40, the air outlet 24 and the second connection pipe 23. While the air flows outside, along the outside of the grill assembly 40, some of the contaminants entrained in the air are trapped by the fine holes 43a of the grill assembly 40, and fall into the dust receptacle 30.
Contaminants which are not separated by the centrifugal force of the whirling air and thus are still entrained in the air are discharged to the air outlet 24 through the fine holes 43a of the grill assembly 40, but are filtered at a paper filter in the cleaner body and the cleaned air is discharged out of the cleaner by the motor and vacuum-inducing blower (not shown).
In a vacuum cleaner having the cyclone-type dust collecting apparatus described above, dust and filth entrained in the air drawn into the suction port of the cleaner are firstly filtered and collected by the cyclone-type dust collecting apparatus, and as a result, the amount of contaminants that the paper filter has to filter decreases.
The conventional cyclone-type dust collecting apparatus for a vacuum cleaner described above, however, has some problems. That is, as shown in FIG. 2, the plurality of fine holes 43a of the grill assembly 40 are formed at an angle approximately of 90° with respect to a stream line B of the whirling air in the cyclone-type dust collecting apparatus, and the contaminants entrained in the whirling air are easily drawn into the cleaner body through the fine holes 43a in the direction indicated by dotted arrows of FIG. 2. Since the conventional cyclone-type dust collecting apparatus for vacuum cleaner does not have any means to filter fine contaminants that are more minute than the fine holes 43a, most of fine contaminants are drawn into the cleaner body through the fine holes 43a and, accordingly, the contaminants being filtered at the paper filter increase. As a result, the lifespan of the paper filter is shortened.
Another problem of the conventional vacuum cleaner cyclone-type dust collecting apparatus is that some contaminants are not discharged but instead adhere to the fine holes 43a of the grill assembly 40 as the air flows through the fine holes 43a. As time goes by, the contaminants clog the fine holes 43a, causing problems like suction force deterioration and motor overload. Accordingly, the contaminants at the fine holes 43a have to be removed regularly. However, the structural characteristic of the grill assembly makes it hard for a user to clean the grill, causing inconvenience to the user.